Rock drill



Patented Dec. 26, 1944 ROCK DRILL John C. Curtis and Elmer GLGartin. Claremont,

N. H., assignors to Sullivan Machinery Company, a corporation of Massachusetts Application september 1s, 1941, serial No. 411,285

Claims.

This invention relates to rock drills and more particularly has reference to a drill steel guide especially designed for use with a hammer rock drill.

An object of the present invention is to provide an improved drill steel guide. Another object is to provide an improved drill steel guide having novel means for locking the guiding elements thereof in steel guiding position, and wherein the locking means is automatically releasable by engagement of the hammer motor therewith. A further object is to* provide a novel means for automatically moving the guiding elements into their released non-guiding position when lthe locking means is released. Still another object is to provide an improved drillvsteel guide of the pivoted arm type having a novel latch means for locking the guidearms in steel guiding position. A still further object is to provide improved means for limiting swinging movement of the gu'de arms in either dire-ction about their pivotal axes. "Yet another obpject is to provide an improved pivotal mounting structure for the guide arms of a drill steel guide. A further object is to provide an improved latch arrangement for locking the guide arms in guiding position, wherein the latch is automatically releasableby engagement of the hammer motor therewith as the latter is fed forwardly along its guiding support. Other and further objects and their resultant advantages will be apparent after the invention becomes better understood Vfrom an examination of the specification and claims in connection with the accompanying drawing in which the 4application of the invention is illustrated.

In the drawing:

I Fig. 1 is a fragmentary plan view .of a hammer rockdrill-with which the improved drill steel guide is associated.

Fig. 2 is a side elevational view. of the rock drill and steel guide shown in Fig. 1.

Fig. 3 is a cro-ss sectional view taken substantially on line 3-3 of Fig. 2, showing the guide arms in steel guiding position.

Fig. 4 is a view similar to Fig. 3, showing the guide arms in their released non-guiding position.

Fig. 5 is a cross sectional View taken substantially on line 5-5 of Fig. 2.

Fig. 6 is a detail view in longitudinal vertical section taken substantially on line 6 6 of Fig. l, showing the improved latch.

In-this illustrative embodiment of the invention the improved drill steel guide, generally designated I is. shown associated with a con-A ventional hammer rock drill of the mounted drifter type. AIt will be evident, however, that the drill steel guide may be lassociated with drills of other types'.

The hammer rock drill comprises a conventional drill hammer motor 2 slidably guided on a conventional guide shell 3, the latter being adapted to be mounted on a conventional drill support. The hammer motor has a motor cylind'er Il containing a usual reciprocatoryhammer piston (not shown) for percussively actuating a drill 'steel 5, the latter being supported in a usual chuck within a chuck housing I5 suitably attached to the front end of the motor cylinder. The hammer motor cylinder 4 has lateral guides l, 'I slidingly received within longitudinal guideways 8, 8 of the guide shell. The hammer motor may be fed along the shell guideways by means of a conventional feed screw engaged with a feed nut carried by the motor cylinder so that when the feed screw is rotated, the hammer motor is fed longitudinally relative to the guide shell. Since, as above stated, the rock drill is of a, conventional design and is well known to those skilled in the art, further description and illustration thereof are unnecessary.

Now referring to the improved drill steel guide I, it Vwill be noted that attached by the shell tie .bolts 9 and a bolt I0 to the forward end of the g-uide shell is a pair of transversely arranged, parallel supporting plates II and I2, and these plates are held in proper spaced relation by spacing sleeves I3 interposed between the plates and arranged on the bolts 9 and Il. The top surfaces of the plates are disposed below the 4plane projections of the bottom surfaces of the vshell guideways, so that the drill hammer may move forwardly above the plates when the guide arms are in their wide open position. The rear plate I I has an integral bearing boss I4 in which the forward bearing portion I5 of the feed screw is journaled. Pivotally mounted on the spacing sleeves I3 on the upper tie bolts 9 between the .plates II and I2 is a pair of cooperating guide arms I6, I6 having appropriately shaped guiding portions I'I. The guiding portions of the guide .arms are adapted to embrace the body of the drill steel to hold the latter centered during the starting or spotting of a hole in the manner ,well known to those skilled in the art. A torsion spring I8 encircles the spacing sleeve on the lower bolt I0 intermediate the arm pivot axes, and has its ends respectively engaging depending armlike lugs I9 integral with the guide arms, and this spring constantly urges the guide arms toward their wide open non-guiding position. The ends of the torsion spring are attached to the arm lugs I9 by means of suitable pins 20. fitted within openings in the lugs. Abutment surfaces 2| on the arm lugs I9 are engageable with abutment surfaces 22 on the rear plate I l for limiting outward swinging movement of the guide arms, and when the latter are in their released non-guiding position shown in Fig. 4, the torsion spring yieldingly maintains these surfaces' in abutting engagement. Formed on the guide arms at their inner sides are 'projecting lugs 23 engageable with abutment sur-4 faces 24 on the rear plate H for limiting inward i swinging movement of the guide arms. Guided for axial movement in a bore 25 in one of the guide arms I6 is a boltlike portion 2B of a latch 21, this boltlike portion lhaving threaded on its rear end a flanged nut 28. The guiding bore 25 is arranged with its axis parallel to the longi- .tudinal axis of the rock drill, so that the latch is reciprocable longitudinally of the drill. Encircling the bolt portion 26 and interposed between the rear surface of the guide arm and the 'ange on the nut is a coil vspring 29 for yieldingly urging latch 21 vtoward its rearmost position. The guide arm is recessed at 3U to receive the latch 21, and provides an abutment surface y3l against which Aa rear 'surface 32 on the latch is yieldingly held in abutting engagement by the coil spring. ''helatch '2`1 has a locking lug 33 engageable with a projection 3'4 on the other guide arm so 'that when the latch is yin the position shown in'Fig. 1, the guide arms are locked in steel guiding position with the lugs 2'3 in engagement with the abutment surfaces 24 on the rear .plate l I. The lug 33 has an 'inclined wedging surface 35 so that when the guide arms are l swung inwardly together, this inclined surface engages Vthe inner surface of 'the arm projection Sli to cause 'the latch to spring forwardly 'past the arm lprojection 34 and thereafter to snap inwardly into its latching position. The latch 2l,v

which ts in 'the vrecess 3'0, Ais of such cross section as to prevent rotation o'f the bo'ltlike portion 26 within its bore.

In the operation of the improved drill steel guide, when it is desired to start 'or lspo 'a 'drill hole, the guide arms it, I6 may be swung about their lpivots into the position lshown in Fig. 3 4with their guiding portions 11 in engagement with the drill steel v'5, and Aat-that time thev arms are locked in steel guiding position bythe lug 33l o'f the latch engaging the arm projection 34 (see Fig. l). As the drill hammer motor is fed forwardly along the shell guideways, the 'front chuck housing 6 engages the rear surface iof the nut 28 `and shoves the latch y21 forwardly axially with respect to the 'guide arms to elf'ect release of the locking lug 33 from the 'arm projection 3l. When the latch is released, the torsion spring i8 'automatically swings the guideV arms into their wide open non-*guiding position shown in Fig. '4 so that the harrnner motor can move forwardly between the guide arms without interference therewith. `When the drill hammer motor is again in its retracted position onl the guide shell, the guide arms maybe swung Lmanually against the tension of the torsion spring into their steel guiding position shown in Fig. 3, and as the guide arms are swung together the inclined wedging surface 35 `on the latch engages the inner surface of the arm 'projection 34- so that the latch automaticallyI isn'aps into -it's locked position shown, thereby to hold the guide arms in steel guiding position.

As a result of `this invention, it will be noted that an improved drill steel is provided having improved latching means whereby the guide arms are positively locked in their steel guiding position, and which is releasable by engagement of the drill vhammer motor therewith as the hammer motor is fed forwardly along the guideways of its supporting guide. It will also be noted that by the provision of the torsion spring the arms are automatically swung into the released non-guiding position when the latch is released. By means of the particular arrangement of abutment surfaces on the guide arms, swinging movement of the latter is limited in either direc tion. Other uses and advantages of the invention will be clearly apparent to those skilled in `the art.

While there is in this application specifically described one form which the invention may assurr'lev in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its. spiritr or the scope of the appended claims.

lWhat we claim as new and desi-re to secure by Letters Patent is:

l. In a drill steel guide, a support, a pair of guide arms, pivotally mounted on said support to swing toward and from one another into and out of steel guiding position, a latch guided on one of said guide arms for movement relative thereto in a direction parallel to the longitudinal axis of the drill steel, said latch being engageable with said other guide arm when said arms are together for locking said guide arms in steel guiding position, and operating means for said latch for moving the latter longitudinally relative to said arms to free the latter for swinging` movement from one another.

2. In a drill steel guide, a support, a pair of guide arms pivotally mounted on said support to `swing toward and from one another into and out of -steel guiding position, a latch guided on one of said guide arms :for movement vrelative thereto ina direction parallel to the longitudinal axis of the drillsteel, said latch being engageable with said other guide arm when said guide arms are together for locking said guide arms in steel guiding position, operating means for said latch lfor moving the latter longitudinally relative to said arms to free 4the latter for swinging movementA fromv one another, and 'constantly acti-ng means for automatically swinging said arms apart into their released non-guiding position when said latch is released.

3. In a drill steel guide, 'a support, la pair of guide arms* pivotally mounted lon said support to swing into and out of steel guiding position, one of `said arms having a bore "extending in a direction parallel to the longitudinal axisV of the drill steel, said bore being located :in adjacency to the steelzen'gagingend of said'arm, anda latch guided for reciprocatoryA movement 'in fsaid bore andengageable with said other guide arm to lock said arms in steel guiding position.

4. In a drill steel guide, a support, a .pair of guide arms `pivotally mounted von said support to swing :into and 'out 'of :steel .guiding position, one

for reciprocatory movement in said bore and engageable with said other guide arm to lock said arms in steel guiding position, said latch having a transverse portion and a rearwardly projecting locking lug, and said guide arm with which said latch-engages having a projection with which said lug cooperates.

5. In a rock drill, a supporting guide providing guideways extending to the forward end thereof and along'which a drill steel actuator is guided for movement, said guide having longitudinal tie bolts extending along the sides thereof in close adjacency to the longitudinal planes in which both of said guideways lie, a support attached to the front end of said guide by said tie bolts and extending across the forward end thereof but leaving said guideways unobstructed, and a pair of guide arms pivotally supported by said tie bolts and swingable about their pivots into and out of their steel guiding position.

6. In a rock drill, a supporting guide along which a drill steel actuator is guided for movement,` said guide having longitudinal tie bolts extending along the sides thereof and a feed screw extending longitudinally thereof between thesides thereof, a support attached to the front end of said guide by said tie bolts and providing a bearing for said feed screw, and a pair of guide arms pivotally supported by said tie bolts and swingable about their pivots into and out of their steel guiding position, said support including front and which a drill steel actuator is guided for movement, and a drill steel guide attached to the front end of said guide including cooperating relatively movable guiding elements, latching means reciprocably guided on one of said guiding elements for movement relative thereto along a line parbeing engageable with said operating means to rear plates supported by said tie bolts'and said arms being pivotally mounted on said tie bolts intermediate said plates.

7. In a. rock drill, a supporting guide along which a drill steel actuator is guided for movement, and a drill steel guide attached to the front end of said guide including cooperating relatively movable guiding elements, latching means reciprocably guided on one of said guiding elements for movement relative thereto and engageable with said other element to lock said elements together in steel guiding position, and operating meansr for said latching means disposed in the path of movement of said steel actuator for moving said latching means relative to said guiding elements for freeing the latter for movement away from the drill steel, said steel actuator as it moves forwardl'y along said supporting guide being engageable with said operating means to effect release of said latching means.

8. In a rock drill, a supportingl guide along /eifect release of said latching means.

9. In a rock drill, a supporting guide along which a drill steel actuator is guided for movement, and a drill steel guide attached to the front end of said guide including cooperating relative movable guiding elements, latching means reciprocably guided on one of said guiding elements for movement relative thereto and engageable with saidother element to lock said-elements together in steel guiding position, operating means for said latching means disposed in the path of movement of said steel actuator for moving said latching means relative to said guiding elements for freeing the latter for movement away from the drill steel, said steel actuator as it moves forwardly along said supporting guide being engageable with said operating means to eiect release of said latching means, and constantly acting means for automatically moving said guiding elements apart into their released non-guiding position when said latching means is released.

10. In a drill steel guide, a support, a pair of guide arms pivotally mounted on said support to swing toward and from one another into and out of steel guiding position, a latch guided on one of said guide arms for movement relative thereto in planes parallel to the longitudinal axis of the drill steel, said latch being engageable with said other guide arm when said arms are together for locking said guide arms in steel guiding position, and operating means for said latch for moving the latter longitudinally relative to said guide arms for freeing the latter for swinging movement from one another.

JOHN C. CURTIS. ELMER G. GARTIN. 

